Vitamin A in diets for Nile tilapia

Abstract

Dietary vitamin supplementation decrease stress caused by high stocking density, and boosts immunological system of farmed fish. A studied was carried out to determine vitamin A requirements of Nile tilapia (Oreochromis niloticus) in an all male group (13.8 ± 1.2 g) and a mixed sex population (9.8 ± 2.3 g). Fish stocked in 100-L plastic aquaria (26.0 ± 1.0ºC) were fed to near satiety, twice a day, seven days a week, during 75 days with vitamin A-free, semi-purified diets supplemented with 0; 600; 1,200; 1,800; 2,400; 3,000; 3,600; 4,200; 4,800 and 5,400 International Units (IU) of retinyl palmitate (30% vitamin A) per kg of diet in a completely randomized experimental design, factorial arrangement 2χ10 (n = 4). Deficiency signs of vitamin A were observed in fish fed 0 to 1.200 IU vitamin A kg -1 diet; moderate signs were observed in fish fed diets with 1.800 to 3.600 IU vitamin A kg -1 diet; no interactions group*level (p < 0.05) were detected. Dietary levels of vitamin A up to 5.400 IU kg -1 influenced final weight and weight gain of fish (p < 0.05), but did not influence feed consumption (p > 0.05). A group effect was observed regarding all performance variables (p < 0.0001). Quantification of hepatic retinol (HPLC) detected vitamin A only in fish fed 5.400 IU retinol kg -1 of diet, therefore characterizing that dietary retinol was used and stored. The quantity of 5.400 IU of retinol kg -1 of diet is recommended for adequate nutrition of Nile tilapia.

Vitamin A affects haematology, growth and immune response of Nile tilapia (Oreochromis niloticus, L.), but has no protective effect against bacterial challenge or cold-induced stress

“…The estimated vitA requirement to maintain proper growth and prevent deficiency signs in this study (1.2-1.38 mg ROH kg À1 ) was similar to our previous study on tilapia using a purified diet (1.17 mg ROH kg À1 ) (Guimarães et al 2013). Previous reports on hybrid tilapia (Hu et al 2006) and Nile tilapia (Saleh et al 1995;Campeche et al 2009) have estimated the requirement ranging from 1.76 to 2.09 mg ROH kg À1 , and 1.5 to 1.62 mg ROH kg À1 respectively. Differences on the experimental length, feed processing, genetic line and statistical model used to estimate the requirement may induce significant differences between studies.…”

“…VitA deficient fish showed restless behaviour, erratic swimming, exophthalmia, haemorrhages on skin and base of the fins, and ascites. These vitA deficiency symptoms have been previously reported in tilapia (Saleh et al 1995;Campeche, Catharino, Godoy & Cyrino 2009;Guimarães et al 2013) and other fish species (Kitamura, Suwa, Ohara & Nak- Values are means of two determinations per fish, two fish per tank and four tanks per treatment. Significant differences (P < 0.05) between before (■) and after stress ( ) are denoted by an asterisk above the bars.…”

“…These vitA deficiency symptoms have been previously reported in tilapia (Saleh et al . ; Campeche, Catharino, Godoy & Cyrino ; Guimarães et al . ) and other fish species (Kitamura, Suwa, Ohara & Nakagawa ; Poston & Livingston ; Halver ; Shaik Mohamed et al .…”

“…; Campeche et al . ) have estimated the requirement ranging from 1.76 to 2.09 mg ROH kg −1 , and 1.5 to 1.62 mg ROH kg −1 respectively. Differences on the experimental length, feed processing, genetic line and statistical model used to estimate the requirement may induce significant differences between studies.…”

Dietary vitamin A requirement ofSillago sihamaForskál

“…From the sixth week, vitamin A deficiency which included inanimate, haemorrhages on the head, erosion of skin, and greater mortality was observed in the fish fed the basal diets. Similar results about vitamin A deficiency signs were reported on Nile tilapia, Oreochromis niloticus (Campeche, Catharino, Godoy & Cyrino, ; Guimarães et al., ), juvenile Amur sturgeon, Acipenser schrenckii (Wen, Yan, Gao, Jiang & Wei, ), juvenile greasy grouper, Epinephelus tauvina (Mohamed et al., ), and juvenile Jian carp, Cyprinus carpio (Yang, Zhou, Jiang & Yang, ). However, other signs like exophthalmia (Yang et al., ) and blind eyes (Saleh, Eleraky & Gropp, ) were not found in this study.…”